The invention relates to a thermostatic valve for a cooling system of an internal combustion engine, having a thermostatic operating element to be arranged in a valve chamber, which is used as the drive element for a main valve element to be arranged between an engine outlet and a connector leading to a coolant cooler, and for a bypass valve element, which is designed as a valve slide, to be arranged between the engine outlet and an engine inlet and which has a pressure control valve function.
In order to shorten the warm-up phase when starting an internal combustion engine with cold coolant, and to improve the combustion by means thereof, it is known to keep the main valve, as well as the bypass valve, closed during the warm-up phase. To avoid thermal and/or mechanical damage to the internal combustion engine and associated components when the internal combustion engine in the cold state is operated at high engine rpm, a pressure control valve is provided, which opens at increased engine rpm and correspondingly increased pressure and allows a flow of coolant from the engine outlet to the engine inlet. In this connection it is known (German Patent Publication DE 102004021009 A1) to design the bypass valve element as a pressure control valve.